Reliable Outcomes Provided by a Rotating Hinge Knee Arthroplasty for Patients Who Have Moderate-To-Severe Arthrofibrosis.

BACKGROUND

Idiopathic arthrofibrosis after total knee arthroplasty (TKA) is a challenging complication resulting in stiffness and pain. Modern rotating-hinge (RH) prostheses have gained popularity for managing arthrofibrosis during revision TKA. The primary aim of this study was to evaluate the effectiveness of revision TKA using an RH prosthesis on improving range of motion (ROM) for patients who have moderate and severe arthrofibrosis. The secondary aim was to evaluate the survivorship of these prostheses.

METHODS

This was a retrospective study of all patients who underwent revision TKA for a diagnosis of arthrofibrosis with an RH prosthesis at a single arthroplasty center between 2014 and 2023. There were 41 patients with a mean follow-up of 3.6 years (SD: 2.5) included. Knee ROM measurements were collected preoperatively, at six weeks, 12 weeks, and one year postoperatively. Postoperative complications were recorded. Differences in arc of ROM for each patient between time points were assessed using analysis of variance. Kaplan-Meier survival analysis with log-rank test was performed for complications requiring reoperation.

RESULTS

Mean preoperative ROM, maximum flexion, and maximum extension were 52.7 degrees (SD: 20.1, range, 10 to 90), 68.5 degrees (SD: 21.3, range, 30 to 120), and 15.7 degrees (SD: 14.5, range, 0 to 90), respectively. There was a significantly greater ROM, maximum extension, and maximum flexion at six weeks, 12 weeks, and one year (P < 0.05 for all). At 1 year, mean improvement in ROM was 34.7 degrees (SD: 26.8, range, -34 to 85), and mean ROM was 89.5 degrees (SD: 20.6, range, 46 to 130). Implant survivorship at final follow-up was 90.2%.

CONCLUSIONS

Revision TKA with RH prosthesis is effective for the management of idiopathic arthrofibrosis after TKA, resulting in significant improvements in ROM with acceptable short-to-mid-term survivorship. Multicenter, prospective studies with long-term follow-up are warranted to validate these findings.